Quantum simulation

Using particle-by-particle assembly and adiabatic manipulation of disorder, low-entropy, strongly correlated quantum fluids of light are constructed, opening up new possibilities for the preparation of exotic phases of synthetic matter.

Multistability is the possibility of a dissipative quantum many-body system to have multiple steady states - it is intensely studied, but its existence remains controversial. The paper settles this by providing an exactly provable case, and also proves that boundary time crystals can exist in interacting lattice models, which was not known before.

An experimental investigation of the dynamics of the spin ½ Floquet XXZ model finds bound states as predicted, and also robustness to noise and non-integrability when theoretical descriptions start to fail.

Randomized measurements provide a feasible procedure for probing properties of many-body quantum states realized in today’s quantum simulators and quantum computers. This Review covers implementation, classical post-processing and theoretical performance guarantees of randomized measurement protocols, surveying their many applications and discussing current challenges.

Quantum simulators allow for experimental studies of many-body systems in complex geometries, which has rarely been addressed by theory. Here the authors study many-body Hamiltonians on generic random graphs and show that many-body effects emerge only in a small class of exceptional, highly structured graphs.